The Standards Determination Committee for LTE (Long Term Evolution)-Advanced schemes has proposed adaptation of a contention-based uplink transmission control method using “Contention Based Grant” (see Non-Patent Document 1). A contention-based uplink transmission control method using the “Contention Based Grant” will be simply described below.
Firstly, in addition to an uplink scheduling grant transmitted through PDCCH (Physical Downlink Control Channel) addressed to C-RNTI (Cell-Radio Network Temporary Identity) of a mobile station UE, the mobile station UE can monitor and receive an uplink scheduling grant transmitted though the PDCCH addressed to CB-RNTI (Contention Based-Radio Network Temporary Identity).
Secondly, when the mobile station UE has received an uplink scheduling grant transmitted though PDCCH addressed to CB-RNTI, an uplink data signal is transmitted through PUSCH (Physical Uplink Shared Channel) using TF (Transmission Format), MCS (Modulation and Code Scheme), RB (Resource Blocks) or the like that are designated by the uplink scheduling grant.
The mobile station UE adds “MAC CE (Control Element)” including the C-RNTI of the mobile station UE to the uplink data signal to enable identification of by whom the uplink data signal has been transmitted.
As a result, application of the contention-based uplink transmission control method using the “Contention Based Grant” is expected to be capable of a reduction in transmission delay of the uplink data signal by enabling omission of the L2 procedure of “transmission of scheduling request by mobile station UE”→“transmission of uplink scheduling grant by radio base station eNB”, →“transmission of buffer status report by mobile station UE”, →“transmission of uplink scheduling grant by radio base station eNB”, →“transmission of uplink data signal by mobile station UE”.
Application of contention-based uplink transmission control method using “Contention Based Grant” is expected to be capable of effective application to uplink resources that are not used after normal scheduling addressed to the C-RNTI.